I'm just finishing my studies at the University. I have been given the opportunity to live in Russia for a semester and learn the language. I want to continue my learning of that language as well as begin to learn Japanese. I want to become fluent in bother of those languages. Where would I learn these languages or how would I learn these languages without going back to school for another degree???
Since you can't live in both places (at least not comfortably), you should probably just live in Russia or Japan and get a friend of the other nationality.
I guess you'd be better off livin in Japan getting a Russian friend. Russia and most Russians are awesome, but Russia, mostly, is not. But it may be hard finding a lot of Russians in Japan (not entirely sure), while I think finding Japanese in Russians will be easier (there's lots in Moscow).
Hokkaido is relatively close to Russia, despite it being the nearly vacant part of the country.
If you're serious about continuing your Japanese study and you're a UK resident you could try the JET Scheme. Japanese Government sponsored programme - you'll be a teaching assistant in Japanese schools and in return they'll pay for pretty much everything out there.
Website is http://www.jet-uk.org/